Thin-wall molded products to be used in the light electric appliance field or other fields require high flame retardancy in addition to thermal or heat resistance due to soldering, stiffness, and mechanical strength for impact or stress. An aromatic polyetherketone resin, such as a polyetheretherketone (PEEK), is known as a super engineering plastic having excellent heat resistance and mechanical properties. Although the aromatic polyetherketone resin is a material having a high oxygen index and a high flame retardancy, the resin is not absolutely unburnable. A thin-wall molded product of the resin, which is violently oxidized and decomposed by burning, has still insufficient flame retardancy.
WO2012/005133 (Patent Document 1) discloses a resin composition for improvement of sliding properties and impact resistance, wherein the resin composition comprises an aromatic polyetherketone resin and a fluorine-containing resin, the fluorine-containing resin is a copolymer of tetrafluoroethylene and a perfluoroethylenically unsaturated compound, the mass ratio of the aromatic polyetherketone resin and the fluorine-containing resin is 95:5 to 50:50, the fluorine-containing resin is dispersed as particles in the aromatic polyetherketone resin and has an average dispersed particle diameter of not more than 3 μm. The Examples of the document disclose an embodiment in which the aromatic polyetherketone resin and the fluorine-containing resin were used in a mass ratio of 80:20 to 60:40 to prepare a molded article having a thickness of 3 mm.
Japanese Patent Application Laid-Open Publication No. 2006-274073 (JP-2006-274073A, Patent Document 2) discloses a resin composition for improvement of external appearance, slipping properties, solvent resistance, and heat resistance in a thin molded article (such as a film), wherein the resin composition comprises 70 to 99% by mass of a polyarylketone resin (e.g., a polyetheretherketone) and 30 to 1% by mass of a micro-powdery fluorine-containing resin, the fluorine-containing resin is dispersed in the resin composition and has an average particle diameter of 0.1 to 30 μm. This document discloses that a polytetrafluoroethylene (PTFE) is particularly preferred. In Examples of the document, a PTFE was used in an amount of 10 to 20% by weight.
Unfortunately, these documents fail to disclose the flame retardancy of these resin compositions.